[PATCH v5 09/14] x86: Add support for PUD-sized transparent hugepages

From: Matthew Wilcox
Date: Thu Mar 10 2016 - 18:56:14 EST

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From: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>

The x86-specific code needed to support the PUD uses in the transparent
hugepages code.

Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/paravirt.h | 11 +++
arch/x86/include/asm/paravirt_types.h | 2 +
arch/x86/include/asm/pgtable-2level.h | 13 +++
arch/x86/include/asm/pgtable-3level.h | 20 +++++
arch/x86/include/asm/pgtable.h | 147 ++++++++++++++++++++++++++++++++++
arch/x86/include/asm/pgtable_64.h | 5 ++
arch/x86/kernel/paravirt.c | 1 +
arch/x86/mm/pgtable.c | 31 +++++++
9 files changed, 231 insertions(+)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3b8290c..d28cc92 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -91,6 +91,7 @@ config X86
select HAVE_ARCH_SOFT_DIRTY if X86_64
select HAVE_ARCH_TRACEHOOK
select HAVE_ARCH_TRANSPARENT_HUGEPAGE
+ select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
select HAVE_BPF_JIT if X86_64
select HAVE_CC_STACKPROTECTOR
select HAVE_CMPXCHG_DOUBLE
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 601f1b8..8fd5e50 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -486,6 +486,17 @@ static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
native_pmd_val(pmd));
}

+static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
+ pud_t *pudp, pud_t pud)
+{
+ if (sizeof(pudval_t) > sizeof(long))
+ /* 5 arg words */
+ pv_mmu_ops.set_pud_at(mm, addr, pudp, pud);
+ else
+ PVOP_VCALL4(pv_mmu_ops.set_pud_at, mm, addr, pudp,
+ native_pud_val(pud));
+}
+
static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
{
pmdval_t val = native_pmd_val(pmd);
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index e8c2326..38f416e 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -252,6 +252,8 @@ struct pv_mmu_ops {
void (*set_pmd)(pmd_t *pmdp, pmd_t pmdval);
void (*set_pmd_at)(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmdval);
+ void (*set_pud_at)(struct mm_struct *mm, unsigned long addr,
+ pud_t *pudp, pud_t pudval);
void (*pte_update)(struct mm_struct *mm, unsigned long addr,
pte_t *ptep);

diff --git a/arch/x86/include/asm/pgtable-2level.h b/arch/x86/include/asm/pgtable-2level.h
index 2f558ba..38f55ed 100644
--- a/arch/x86/include/asm/pgtable-2level.h
+++ b/arch/x86/include/asm/pgtable-2level.h
@@ -21,6 +21,10 @@ static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
*pmdp = pmd;
}

+static inline void native_set_pud(pud_t *pudp, pud_t pud)
+{
+}
+
static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
{
native_set_pte(ptep, pte);
@@ -31,6 +35,10 @@ static inline void native_pmd_clear(pmd_t *pmdp)
native_set_pmd(pmdp, __pmd(0));
}

+static inline void native_pud_clear(pud_t *pudp)
+{
+}
+
static inline void native_pte_clear(struct mm_struct *mm,
unsigned long addr, pte_t *xp)
{
@@ -47,6 +55,11 @@ static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
{
return __pmd(xchg((pmdval_t *)xp, 0));
}
+
+static inline pud_t native_pudp_get_and_clear(pud_t *xp)
+{
+ return __pud(xchg((pudval_t *)xp, 0));
+}
#endif

/* Bit manipulation helper on pte/pgoff entry */
diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h
index b1b6412..fbf6ebc 100644
--- a/arch/x86/include/asm/pgtable-3level.h
+++ b/arch/x86/include/asm/pgtable-3level.h
@@ -169,6 +169,26 @@ static inline pmd_t native_pmdp_get_and_clear(pmd_t *pmdp)

return res.pmd;
}
+
+union split_pud {
+ struct {
+ u32 pud_low;
+ u32 pud_high;
+ };
+ pud_t pud;
+};
+
+static inline pud_t native_pudp_get_and_clear(pud_t *pudp)
+{
+ union split_pud res, *orig = (union split_pud *)pudp;
+
+ /* xchg acts as a barrier before setting of the high bits */
+ res.pud_low = xchg(&orig->pud_low, 0);
+ res.pud_high = orig->pud_high;
+ orig->pud_high = 0;
+
+ return res.pud;
+}
#endif

/* Encode and de-code a swap entry */
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 4cbc459..0343699 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -46,6 +46,7 @@ extern struct mm_struct *pgd_page_get_mm(struct page *page);
#define set_pte(ptep, pte) native_set_pte(ptep, pte)
#define set_pte_at(mm, addr, ptep, pte) native_set_pte_at(mm, addr, ptep, pte)
#define set_pmd_at(mm, addr, pmdp, pmd) native_set_pmd_at(mm, addr, pmdp, pmd)
+#define set_pud_at(mm, addr, pudp, pud) native_set_pud_at(mm, addr, pudp, pud)

#define set_pte_atomic(ptep, pte) \
native_set_pte_atomic(ptep, pte)
@@ -122,6 +123,16 @@ static inline int pmd_young(pmd_t pmd)
return pmd_flags(pmd) & _PAGE_ACCESSED;
}

+static inline int pud_dirty(pud_t pud)
+{
+ return pud_flags(pud) & _PAGE_DIRTY;
+}
+
+static inline int pud_young(pud_t pud)
+{
+ return pud_flags(pud) & _PAGE_ACCESSED;
+}
+
static inline int pte_write(pte_t pte)
{
return pte_flags(pte) & _PAGE_RW;
@@ -175,6 +186,18 @@ static inline int pmd_trans_huge(pmd_t pmd)
return (pmd_val(pmd) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE;
}

+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static inline int pud_trans_huge(pud_t pud)
+{
+ return (pud_val(pud) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE;
+}
+#else
+static inline int pud_trans_huge(pud_t pud)
+{
+ return 0;
+}
+#endif
+
static inline int has_transparent_hugepage(void)
{
return cpu_has_pse;
@@ -185,6 +208,18 @@ static inline int pmd_devmap(pmd_t pmd)
{
return !!(pmd_val(pmd) & _PAGE_DEVMAP);
}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static inline int pud_devmap(pud_t pud)
+{
+ return !!(pud_val(pud) & _PAGE_DEVMAP);
+}
+#else
+static inline int pud_devmap(pud_t pud)
+{
+ return 0;
+}
+#endif
#endif
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

@@ -326,6 +361,65 @@ static inline pmd_t pmd_mknotpresent(pmd_t pmd)
return pmd_clear_flags(pmd, _PAGE_PRESENT | _PAGE_PROTNONE);
}

+static inline pud_t pud_set_flags(pud_t pud, pudval_t set)
+{
+ pudval_t v = native_pud_val(pud);
+
+ return __pud(v | set);
+}
+
+static inline pud_t pud_clear_flags(pud_t pud, pudval_t clear)
+{
+ pudval_t v = native_pud_val(pud);
+
+ return __pud(v & ~clear);
+}
+
+static inline pud_t pud_mkold(pud_t pud)
+{
+ return pud_clear_flags(pud, _PAGE_ACCESSED);
+}
+
+static inline pud_t pud_mkclean(pud_t pud)
+{
+ return pud_clear_flags(pud, _PAGE_DIRTY);
+}
+
+static inline pud_t pud_wrprotect(pud_t pud)
+{
+ return pud_clear_flags(pud, _PAGE_RW);
+}
+
+static inline pud_t pud_mkdirty(pud_t pud)
+{
+ return pud_set_flags(pud, _PAGE_DIRTY | _PAGE_SOFT_DIRTY);
+}
+
+static inline pud_t pud_mkdevmap(pud_t pud)
+{
+ return pud_set_flags(pud, _PAGE_DEVMAP);
+}
+
+static inline pud_t pud_mkhuge(pud_t pud)
+{
+ return pud_set_flags(pud, _PAGE_PSE);
+}
+
+static inline pud_t pud_mkyoung(pud_t pud)
+{
+ return pud_set_flags(pud, _PAGE_ACCESSED);
+}
+
+static inline pud_t pud_mkwrite(pud_t pud)
+{
+ return pud_set_flags(pud, _PAGE_RW);
+}
+
+static inline pud_t pud_mknotpresent(pud_t pud)
+{
+ return pud_clear_flags(pud, _PAGE_PRESENT | _PAGE_PROTNONE);
+}
+
#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
static inline int pte_soft_dirty(pte_t pte)
{
@@ -337,6 +431,11 @@ static inline int pmd_soft_dirty(pmd_t pmd)
return pmd_flags(pmd) & _PAGE_SOFT_DIRTY;
}

+static inline int pud_soft_dirty(pud_t pud)
+{
+ return pud_flags(pud) & _PAGE_SOFT_DIRTY;
+}
+
static inline pte_t pte_mksoft_dirty(pte_t pte)
{
return pte_set_flags(pte, _PAGE_SOFT_DIRTY);
@@ -347,6 +446,11 @@ static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
return pmd_set_flags(pmd, _PAGE_SOFT_DIRTY);
}

+static inline pud_t pud_mksoft_dirty(pud_t pud)
+{
+ return pud_set_flags(pud, _PAGE_SOFT_DIRTY);
+}
+
static inline pte_t pte_clear_soft_dirty(pte_t pte)
{
return pte_clear_flags(pte, _PAGE_SOFT_DIRTY);
@@ -357,6 +461,11 @@ static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
return pmd_clear_flags(pmd, _PAGE_SOFT_DIRTY);
}

+static inline pud_t pud_clear_soft_dirty(pud_t pud)
+{
+ return pud_clear_flags(pud, _PAGE_SOFT_DIRTY);
+}
+
#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */

/*
@@ -385,6 +494,13 @@ static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
massage_pgprot(pgprot));
}

+#define pfn_pud pfn_pud
+static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot)
+{
+ return __pud(((phys_addr_t)page_nr << PAGE_SHIFT) |
+ massage_pgprot(pgprot));
+}
+
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
pteval_t val = pte_val(pte);
@@ -740,9 +856,18 @@ static inline pmd_t native_local_pmdp_get_and_clear(pmd_t *pmdp)
return res;
}

+static inline pud_t native_local_pudp_get_and_clear(pud_t *pudp)
+{
+ pud_t res = *pudp;
+
+ native_pud_clear(pudp);
+ return res;
+}
+
#ifndef CONFIG_SMP
#define native_ptep_get_and_clear(p) native_local_ptep_get_and_clear(p)
#define native_pmdp_get_and_clear(p) native_local_pmdp_get_and_clear(p)
+#define native_pudp_get_and_clear(p) native_local_pudp_get_and_clear(p)
#endif

static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
@@ -757,6 +882,12 @@ static inline void native_set_pmd_at(struct mm_struct *mm, unsigned long addr,
native_set_pmd(pmdp, pmd);
}

+static inline void native_set_pud_at(struct mm_struct *mm, unsigned long addr,
+ pud_t *pudp, pud_t pud)
+{
+ native_set_pud(pudp, pud);
+}
+
#ifndef CONFIG_PARAVIRT
/*
* Rules for using pte_update - it must be called after any PTE update which
@@ -835,10 +966,15 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm,
extern int pmdp_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp,
pmd_t entry, int dirty);
+extern int pudp_set_access_flags(struct vm_area_struct *vma,
+ unsigned long address, pud_t *pudp,
+ pud_t entry, int dirty);

#define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
extern int pmdp_test_and_clear_young(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmdp);
+extern int pudp_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long addr, pud_t *pudp);

#define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
@@ -858,6 +994,13 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
return native_pmdp_get_and_clear(pmdp);
}

+#define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
+static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
+ unsigned long addr, pud_t *pudp)
+{
+ return native_pudp_get_and_clear(pudp);
+}
+
#define __HAVE_ARCH_PMDP_SET_WRPROTECT
static inline void pmdp_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pmd_t *pmdp)
@@ -906,6 +1049,10 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
unsigned long addr, pmd_t *pmd)
{
}
+static inline void update_mmu_cache_pud(struct vm_area_struct *vma,
+ unsigned long addr, pud_t *pud)
+{
+}

#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index a0c0219..d264589 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -80,6 +80,11 @@ static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
{
return native_make_pmd(xchg(&xp->pmd, 0));
}
+
+static inline pud_t native_pudp_get_and_clear(pud_t *pudp)
+{
+ return native_make_pud(xchg(&pudp->pud, 0));
+}
#endif

static inline void native_set_pud(pud_t *pudp, pud_t pud)
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index f08ac28..24d61f2 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -425,6 +425,7 @@ struct pv_mmu_ops pv_mmu_ops = {
.pmd_clear = native_pmd_clear,
#endif
.set_pud = native_set_pud,
+ .set_pud_at = native_set_pud_at,

.pmd_val = PTE_IDENT,
.make_pmd = PTE_IDENT,
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 4eb287e..b7c8df6 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -441,6 +441,26 @@ int pmdp_set_access_flags(struct vm_area_struct *vma,

return changed;
}
+
+int pudp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
+ pud_t *pudp, pud_t entry, int dirty)
+{
+ int changed = !pud_same(*pudp, entry);
+
+ VM_BUG_ON(address & ~HPAGE_PUD_MASK);
+
+ if (changed && dirty) {
+ *pudp = entry;
+ /*
+ * We had a write-protection fault here and changed the pud
+ * to to more permissive. No need to flush the TLB for that,
+ * #PF is architecturally guaranteed to do that and in the
+ * worst-case we'll generate a spurious fault.
+ */
+ }
+
+ return changed;
+}
#endif

int ptep_test_and_clear_young(struct vm_area_struct *vma,
@@ -470,6 +490,17 @@ int pmdp_test_and_clear_young(struct vm_area_struct *vma,

return ret;
}
+int pudp_test_and_clear_young(struct vm_area_struct *vma,
+ unsigned long addr, pud_t *pudp)
+{
+ int ret = 0;
+
+ if (pud_young(*pudp))
+ ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
+ (unsigned long *)pudp);
+
+ return ret;
+}
#endif

int ptep_clear_flush_young(struct vm_area_struct *vma,
--
2.7.0

Next message: Matthew Wilcox: "[PATCH v5 14/14] dax: Use vmf->pgoff in fault handlers"
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Next in thread: Matthew Wilcox: "[PATCH v5 14/14] dax: Use vmf->pgoff in fault handlers"
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